1. Technical Field
This disclosure generally relates to mobile phone systems, and more specifically relates to macro diversity in a mobile data network with data breakout at the edge of the mobile data network.
2. Background Art
Mobile phones have evolved into “smart phones” that allow a user not only to make a call, but also to access data, such as e-mails, the internet, etc. Mobile phone networks have evolved as well to provide the data services that new mobile devices require. For example, 3G networks cover most of the United States, and allow users high-speed wireless data access on their mobile devices. In addition, phones are not the only devices that can access mobile data networks. Many mobile phone companies provide equipment and services that allow a subscriber to plug a mobile access card into a Universal Serial Bus (USB) port on a laptop computer, and provide wireless internet to the laptop computer through the mobile data network. In addition, some newer mobile phones allow the mobile phone to function as a wireless hotspot, which supports connecting several laptop computers or other wireless devices to the mobile phone, which in turn provides data services via the mobile data network. As time marches on, the amount of data served on mobile data networks will continue to rise exponentially.
Mobile data networks include very expensive hardware and software, so upgrading the capability of existing networks is not an easy thing to do. It is not economically feasible for a mobile network provider to simply replace all older equipment with new equipment due to the expense of replacing the equipment. For example, the next generation wireless network in the United States is the 4G network. Many mobile data network providers are still struggling to get their entire system upgraded to provide 3G data services. Immediately upgrading to 4G equipment is not an economically viable option for most mobile data network providers. In many locations, portions of the mobile data network are connected together by point to point microwave links. These microwave links have limited bandwidth. To significantly boost the throughput of this links requires the microwave links to be replaced with fiber optic cable but this option is very costly.
In a mobile data network there are many basestations with radio antennas to manage communication to/from user equipment such as mobile phones. Within this geographical coverage scheme there exists the possibility of overlapping antennas such that user equipment sees the signals from antennas at different basestations. Macro diversity is a scheme for dealing with several antennas that are transferring the same signal when a cell phone is in an area where the overlapping communication to antennas has occurred, meaning when multiple base station antennas have overlap coverage and are all trying to communicate with the same user equipment. In the standard 3G mobile data network, the receiver macro diversity (antenna combining) is managed by the RNC (Radio Network Controller) where signals from the local antennas are combined and controlled to provide the best overall communication to the user equipment.